The present invention generally relates to heat retaining food service devices and more particularly to heat retentive food servers which use a phase change material as a heat storage medium.
There are numerous food service operations which require the use of heat retentive devices to keep food warm for a period of time until it can be served. For instance, hospitals, nursing homes, hotels and other establishments typically have a central kitchen in which food is prepared. After the food is prepared, it must be transported and delivered, creating a delay between the time the food is prepared and the time the food is served. The delay can be such that the food being served is no longer warm when it reaches the ultimate destination. Therefore, numerous devices have been developed to keep food warm for a period of time after preparation. One approach to keeping food warm has simply been to provide a cover or dome with a layer of insulation material disposed therein which can be placed over a plate. Insulated underbases on which a food bearing dinner plate can be placed have also been utilized. Other devices include servers which can be heated to an elevated temperature. Such servers can keep food warm for a relatively long period of time, and include food covers, or domes, along with food holders, such as plates.
A number of such servers are comprised of a hollow shell with a cavity disposed therein. A heat retentive medium is placed in the cavity so that when the containers are heated, the heat retentive medium will store heat and then release heat to maintain food placed adjacent the server at an elevated temperature. The heat retentive medium typically is a wax, or wax mixture. Because wax liquifies when heated, leakage can be a problem with such servers. Thus, servers utilizing a wax-type of heat retentive medium typically have an additional enclosure within the server to seal the wax so that leakage through the server does not occur. The additional enclosure makes construction of such servers more time consuming and expensive than would be necessary if such additional enclosures were not required.
Thus, there is a need for a heat retaining food service container which can be easily constructed, which provides the desired heat retaining characteristics and which eliminates leakage problems.